Peroxycarboxylic acids and compositions containing such

ABSTRACT

The invention provides a new sub-class or organic peroxyacids comprising N-alkyl substituted peroxytrimellitimide of formula (I) in which R=hydrogen or linear or branched alkyl, which demonstrates an excellent combination of safe-handling and bleach performance rendering the sub-class particularly suitable for use as bleach and/or disinfectant in various bleach, bleach additive or washing compositions. Effective bleaching peroxyacids include those in which R=n propyl, iso-propyl, n butyl, sec-butyl, n pentyl and n heptyl. The invention also comprises processes for making the peroxyacids, compositions containing them and processes for washing and/or bleaching and/or disinfecting employing the invention peroxyacids or compositions containing them.

The present invention relates to peroxycarboxylic acids and moreparticularly to peroxycarboxylic acids which contain within theirstructure an imido linkage, to the preparation of such percarboxylicacids and to their use in bleaching compositions and in washingcompositions.

Organic peroxycarboxylic acids, sometimes alternatively calledpercarboxylic acids or organic peracids, as a class, are potentiallyvery useful oxidising agents as a result of their high redox potentialwhich enables them to bleach very effectively a wide range of stainsthat mark domestic laundry or non-absorbent surfaces in the home and tobe very useful disinfectants or sanitizers on account of their biocidalactivity against a broad spectrum of pathogenic micro-organisms.Self-evidently, some percarboxylic acids are more effective than othersin such activities, but the relative efficacy of the percompounds isonly one key factor in determining the potential usefulness of suchpercompounds because they vary also in a second key area, which is thephysical characteristics of the percompounds and specifically theirsensitivity to impact, pressure or thermal shock and their propensity todecompose during storage, either by themselves or in contact with othercomponents of washing or bleaching compositions. Variation in respect ofboth factors occurs as a direct result of what else is present in thepercarboxylic acid molecule and the structural relationship of forexample the various substituents to the percarboxylic acid group and toeach other.

It is easy for the skilled person in this field to set out a number ofdesiderata; i.e. criteria that a peroxyacid ought to satisfy, in orderto be considered an effective and acceptable bleaching component. If theperoxyacid is being produced in situ, then the criterion of overwhelmingimportance is its performance, i.e. to what extent does it wash andbleach, but if it is being employed as a preformed compound, then anumber of other criteria assume similar importance to its performance,including in particular whether it enjoys sufficient resistance toimpact, friction, pressure and thermal shocks to enable the material tobe formulated, and handled and transported, both before and afterformulation, and also enjoys an acceptably long shelf-storage life, i.e.successful, safe and stable.

The impression may have been fostered that all peroxyacids are similar,as a result of the inclusion of general formulae for peracids in manypatent specifications, e.g. U.S. Pat. No. 4,259,201 of HO--O--(CO)--R--Ywhich appear to equate aliphatic and aromatic peroxyacids and a widerange of substituents. To a limited extent such an impression isjustifiable, in that they do share, in general, a capability ofbleaching domestic stains at lower molar amounts and at lowertemperatures than hydrogen peroxide from which they are usually derived,and they can suffer from a tendency to decompose, either induced byshocks or during storage or interaction with other chemicals or materialsurfaces. However, the various sub-classes of peroxyacids showconsiderable variation in the extent to which they enjoy enhancedbleaching properties or suffer from the tendency to decompose by shockand/or in storage.

One of the sub-classes of peroxyacids tested in the course of thepresent investigations comprised aromatic compounds containing withintheir structure an imide link. A number of peroxyacids in that sub-classhave been described by Ausimont Spa as bleaching agents in EP-A-0 325289, published in August 1989, in which the imido nitrogen atom issubstituted by an alkylene-peroxycarboxylic acid group. However, theperoxyacid that performed best in Ausimont's washing trials,phthalimido-peracetic acid, was found by the present investigators,amongst other things, to suffer from rather poor resistance to impact,even when desensitised by dilution with its own weight of an effectiveinert diluent, sodium sulphate, i.e. was relatively unsafe to handle.The bleach that performed next best in the Ausimont tests,phthalimido-perpropionic acid was found to have lost nearly half itsperoxyacid activity within 4 weeks storage at 32° C., i.e. wasrelatively unstable. Thus, the Ausimont specification did not offer theinvestigators a clear teaching as to how to select safe and stableperoxyacid bleaches.

It remained an objective of the instant investigations to locatealternative peroxyacid bleaches which not only could demonstrateacceptable bleaching performance but could also meet the otherrequirements for practical use, namely safe handling and peroxyacidstability.

Subsequent to the priority date claimed for the instant application, twofurther patent applications were published which disclosed otheraromatic imidoperoxyalkanoic acids, viz EP-A-0 349 940 to Hoescht and WO90/07501 to Interox Chemicals, but neither of those applicationsdescribed any of the novel selection of peroxyacids describedhereinafter.

According to the present invention there is provided an organicperoxyacid which satisfies general formula (1): ##STR2## in which Rrepresents hydrogen or a low molecular weight alkyl group containing upto 8 linear carbon atoms.

The alkyl group, R, can be linear or branched, and normally containsfrom 1 to 10 carbon atoms. Side chains, if present, are normally methyl,ethyl or propyl. It will be understood that whilst all the inventionperacids are good at stain removal, the nature of R influences to anoticeable extent the balance in effectiveness of the invention peracidsat removing various classes of stains. For removal of stains which areclassified as hydrophilic, such as wine, juices or tea, it is preferableto select R from range A, which comprises hydrogen and the somewhatlower weight alkyl group, such as containing up to 5 carbons, includingmethyl, ethyl and propyl, iso-propyl and sec and iso-butyl. For removalbiased towards more hydrophobic stains, such as grass, polish or claystains, it is preferable to employ an overlapping, but somewhat higherrange B of groups for R, such as groups containing from 3 to 8 linearcarbons including iso or sec-butyl, n-pentyl, iso-pentyl, n-heptyl andtrimethyl hexyl. Peracids containing an R group common to both rangesself-evidently are advantageous. Preferred ranges of the inventionperoxyacids which achieve a good balanced performance are those in whichR=linear C4 to C6 and R=branched C3 to C5. In a further preferred set ofperoxycompounds, R is selected such that the number of linear carbonatoms in the only or the longest chain is 3, 5 or 7, though the totalnumber of carbons in R may be even if R is branched.

A mixture of invention peracids can be employed, for example including arepresentative compound in which R is according to each of ranges A andB specified above.

Although the formula above is given in respect of compounds containing asingle peroxytrimellitimido group, it will also be recognised thatcorresponding peroxyacids can be made from the reaction products oftrimellitic anhydride and alkyamines that contain more than one aminegroup, such as alpha-omega alkylene diamines. The resultant peroxyacidsaccordingly can contain a corresponding number of peroxycarboxylic acidgroups per molecule.

The present invention includes compounds containing a plurality ofperoxytrimellitimido groups per molecule and enjoy a similarhydrophobic/hydrophilic balance to the monoperoxytrimellitimido acidsidentified above.

When considering selection of combinations of the various substituentsin peroxyacids, it is of practical value to pay attention to the meltingpoint of purified peroxyacid. As a general guidance, and within eachsub-class of organic peroxyacids, including the sub-class comprising oneaspect of the present invention, it has been found to be more desirableto select those peroxyacids which have the higher or highest apparentmelting points, such as above about 70° C. For many peroxyacids, thistemperature more probably represents the onset of self-acceleratingdecomposition rather than a simple melting point Accordingly, apreferred range of invention peracids comprises compounds in which R ishydrogen, or C1 to C3, or if C4 or larger contains an odd number ofcarbon atoms in the only or longest chain.

From one point of view, peroxytrimellitimide represents an excellentchoice. From the viewpoint of effectiveness as a bleach,peroxytrimellitimides in which R=propyl, iso-propyl, butyl, isobutyl,pentyl or hexyl each represent an excellent choice. Taking into accountall the factors identified herein, the peroxytrimellitimide which hasdemonstrated the best combination of properties to act as a bleach isthat in which R=sec-butyl.

The invention peroxycarboxylic acids can be made by reaction between thecorresponding carboxylic acid and hydrogen peroxide in a strong mineralacid or organic acid reaction medium at a reaction temperature of belowabout 50° C., preferably from 5° to 30° C. maintained until peroxyacidproduct precipitates out of solution, and thereafter separating theproduct from the reaction medium. Most conveniently, a product havingexcellent characteristics can be obtained employing a reaction at aboutambient temperature, i.e. around 20° to 25° C.

It is rather surprising that a sulphuric acid reaction medium can beemployed successfully, because prior art, such as U.S. Pat. Nos.3,143,562 and 3,180,880 to Silbert and Swern, teaches that such a mediumis not applicable to the peroxidation of aromatic peroxycarboxylicacids, i.e. compounds in which the carboxylic acid is a directsubstituent of an aromatic nucleus. Where sulphuric acid was suggestedas the reaction medium for the peroxidation of a sulphoaromaticcarboxylic acid, as in EP-A-0 124 968, to Interox Chemicals Limited, forproduction of a sulphoperbenzoic acid, reaction did occur to a limitedextent, but reaction was rendered practicable by use of analkanesulphonic acid. Similar reaction procedures are known for makingpoorly soluble aliphatic peroxyacids, and these can be applied to themanufacture of the invention peroxyacids. In effect, the processestaught in such prior publications as Siegel, et al in JOC, vol 27pp1336-42 in 1961 entitled peroxides IX. New Method for the DirectPreparation of Aromatic and Aliphatic Peroxyacids can be employed, butmodified as to the carboxylic acid starting materials. Likewise, variousprocesses described for the production of aliphatic peroxyacids in eachof U.S. Pat. No. 2,813,896 (Krimm) U.S. Pat. No. 4,119,660 (Hutchins),U.S. Pat. No. 4,172,086 (Berkowitz), U.S. Pat. No. 4,233,235 (Camden)and U.S. Pat. No. 4,337,213 Marynowski.

Thus, when an organic acid reaction medium for the peroxidationreaction, is employed, it is especially suitably an organic sulphonicacid, such as specifically methane sulphonic acid, which is probably themost readily available lower alkane sulphonic acid. When an inorganicmineral acid reaction medium is employed, it is most preferablysulphuric acid or can alternatively be phosphoric acid. Mixtures of thestrong acids, either wholly inorganic or organic and inorganic, can beemployed if desired.

The carboxylic acid starting material may be introduced into thereaction vessel as a particulate solid or dissolved or slurried in atleast a part of the inorganic or strong organic acid reaction medium.

It will also be recognised that where the reaction medium comprises amineral acid, such as sulphuric acid, all or part of it can be premixedwith the hydrogen peroxide to form an equilibrium mixture containing forexample permonosulphuric acid that can itself perform the peroxidationreaction. Such premixing is beneficial because it separates theexothermic dilution/reaction between hydrogen peroxide and sulphuricacid from the peroxidation reaction, thereby enabling both to becontrolled more readily and safely.

The attention of readers not skilled in the art of peroxygen chemistryis directed to the potentially hazardous nature of peroxidationreactions and their products, to the need to take appropriate safetyprecautions at all times and to control the reaction conditions so as toensure that the reaction mixture never at any time exceeds its SADT,self accelerating decomposition temperature and to carry out any initialtests on a very small scale.

Notwithstanding the above general warning which is of particularrelevance to the formation of many peroxyacids, the isolated peroxyacidsof the instant invention are characterised by their generally benignproperties, specifically their relatively high stability and resistanceto decomposition which they combine with acceptable bleach performance.

It will be recognised that the invention peroxyacids describedhereinbefore are obtainable by peroxidation of the correspondingprecursor imido-containing carboxylic acids, which, if they are notreadily available, can themselves be obtained by a conventionalcondensation between trimellitic anhydride and the appropriate amine orbetween trimellitimide and the appropriate chloroalkane.

Whilst the instant invention relates primarily to the peroxyacidsthemselves, it will be understood that it is possible to form magnesiumsalt derivatives of the peroxyacids by the steps of a) neutralisationusing magnesium oxide or similar compounds in media rendered alkaline toabove the pK_(a) of the peroxyacid and b) recovery of the product thatis permitted or induced to precipitate out. These corresponding saltsshare the same wash performance of the peroxyacids themselves andrepresent an alternative solid vehicle for the peroxyacids.

The percarboxylic acids according to the instant invention areparticulate solids and they can be employed by themselves or can beincorporated as an active bleach component in bleaching or washingcompositions containing a range of other ingredients, the selection andamounts of which are at the discretion of the formulator and determinethe name for the compositions.

Extensive testing of the invention peroxyacids has demonstrated thatthey are less hazardous, as measured by the impact and/or pressure timetest described herein than is diperoxydodecanedioic acid (DPDDA) acurrently favoured benchmark peroxyacid, especially when R=alkyl andthat in general they demonstrate comparable or better storage stabilitythan DPDDA. Thus, all represent an advantageous replacement for DPDDAand those which enjoy the best performance offer an especiallybeneficial combination of properties.

For bleach or bleach additive compositions, the peroxyacid normallycomprises from 1 to 80%, and often from 5 to 50%, all %s herein beingw/w of the respective composition unless otherwise stated The remainder,99 to 20%, comprises a diluent either by itself or together with a minoramount, such as up to 20% in total of optional components such asperoxygen stabilisers, surfactants, etc as indicated subsequentlyherein. The skilled reader will recognise that many of the diluentsdescribed herein as being suitable have hitherto been described as oneor other of desensitising diluents or stabilising diluents or exothermcontrol agents in conjunction with named prior art organic peroxyacidssuch as DPDDA. Whilst the presence of such diluent compounds may havebeen necessary to perform that function for those prior art peroxyacids,it is a significant feature of most of the invention peroxyacids thatthe presence of the same diluents is optional and in practice theirselection can be based upon any other desirable feature of thosecompounds, such as their cheapness or their advantageous washing ordetergent-enhancing properties.

The diluent is often a salt selected from anhydrous or hydrated alkalior alkaline earth metal salts of halogen-free acids, and particularly ofmineral acids, including salts of sulphuric, and ortho, pyro orhexa-meta phosphoric acids. Preferably, the metal is selected fromsodium, potassium and magnesium and in many instances is sodium.Hydrated, partially hydrated or anhydrous sodium sulphate is oftenchosen in view of its widespread availability, its properties and itscost. It will be recognised, though, that use of a phosphate salt may bepreferred in view of its known capabilities of acting as a detergentbuilder, which can complement especially an unbuilt washing composition.

Other inorganic compounds that are suitable for use as diluents includeortho and meta boric acid and alkali metal salts thereof, and especiallysodium salts. Such compounds can buffer solutions of the bleach oradditive composition to a pH in the immediate region of the pK_(a) ofthe peroxyacid and consequently optimise bleach activity. The boricacids have also been used as exotherm control agents in compositionscontaining peroxyacids such as DPDDA that need to be protected against atendency to decompose in an otherwise uncontrollable fashion if allowedto reach a quite low threshold temperature, but that property isunnecessary in conjunction with the invention peroxyacids on account ofthe safe nature of these selected imido peroxyacids.

Other suitable inorganic diluents include alkali metalcarbonates/bicarbonates, aluminium salts of the above-identified mineralacids, and natural or synthetic aluminosilicates and clays, such aszeolites A, X and Y, often in the sodium form, or swelling clays likebentonite, or a layered silicate as described in EP-A-0 337 217. It willbe clearly recognised that many of these diluents also enjoy the statusof builders in washing compositions, and that each accordingly canperform its known functions such as hardness removal or peptising whenemployed in bleach compositions. When the bleach composition is intendedas a scour, at least a proportion of the diluent and preferably at leasthalf of the diluent comprises abrasive powdered materials, includingsilica, quartz, marble dust or kieselguhr.

A further and rather different class of suitable inorganic diluentscomprises alkai metal or alkaline earth metal halides, especiallychlorides and/or bromides and particularly sodium chloride, or sodiumbromide or a mixture of the two. By employing this class of diluents asat least a part of the diluents, the composition can generate insolution during use of the composition a halide such as chlorine orbromine which can complement the bleaching/sanitising effect of theinvention imido peroxyacids.

The diluent can comprise a hydrogen peroxide--developing solid persalt,or an inorganic persulphate, preferably in an amount of not more than50% w/w of the composition. The term "persalt" herein relates primarilyto alkali metal perborates, percarbonates and perphosphates, andespecially the sodium salts, which generate hydrogen peroxide or theHOO⁻ anion depending on the solution pH, in situ and includes otherhydrogen peroxide adducts which can do likewise. Preferred persaltsinclude sodium perborate monohydrate or tetrahydrate and sodiumpercarbonate. Persalts include adducts with urea and related compounds,adducts with certain aluminosilicates and addition compounds withalkali/alkaline earth metal sulphate/chlorides in specified ratios. Itwill be recognised that the use of persalts as diluent, such as in atleast 10% of the composition, enables the composition to be effectivethroughout a range of temperatures from ambient up to about 100° C.

In one more specialised type of bleaching compositions, namelyeffervescent composition, which are often intended primarily forcleansing dentures, but which can also be employed for many otherpurposes, the diluent for the invention peroxyacids preferably containsa gas generating system and if necessary a pH regulator. Compounds thatare suitable for gas generating systems and as pH regulators are wellknown in conjunction with existing peroxyacids, and are described inEP-A-0 133 354 in the name of Interox Chemicals Limited. The gasgenerating system often provides from 10 to 50% and comprises either acarbon dioxide generating combination of an alkali metal carbonate orbicarbonate with a solid water-soluble acid, and especially an organicacid selected from tartaric, citric, lactic, succinic, glutaric, maleic,fumaric and malonic acids, preferably in an equivalent mole ratio offrom 1.5:1 to 1:1.5 and especially at about 1:1, or an oxygen-generatingcompound known as anhydrous sodium perborate, NaBO₃. The pH regulatoroften comprises 5 to 40% of the composition. To provide acidicconditions, it can comprise one or more of the aforementioned organicacids in an appropriate excess amount, or sulphamic acid or alkali metalbisulphates, and to provide alkaline conditions, it can comprise alkalimetal silicates or excess carbonate/bicarbonates. Selection of thepercarboxylic salt form can be advantageous in such compositions.

In the main, the foregoing diluents have been inorganic. However, theinvention peroxyacids can be diluted, if desired, with a range oforganic substances, including hydrocarbon waxes, alkyl C1 to C6 estersof aromatic mono or di carboxylic acids, solid starches, gelatines anddextrins.

The bleach compositions can also contain, as indicated before, minorcomponents such as peroxyacid stabilisers. The breadth of compoundssuitable for this purpose is well-known in this art. These are oftenorganic chelating compounds that sequester metal ions in solution,particularly most transition metal ions, which would promotedecomposition of any peroxygen compounds therein, and many suitable onesbeing classified in the literature as carboxylic acid, hydroxycarboxylicor aminocarboxylic acid complexing agents or as organic amino- orhydroxy-polyphosphonic acid complexing agents, either in acid or solublesalt forms. Representative stabilisers expressed in acid form includepicolinic acid, dipicolinic acid, quinolinic acid, gluconic acid,hydroxyethylene di phosphonic acid, and any compound satisfying thegeneral formula: ##STR3## in which M represents either --CH₂ --CO₂ H or--CH₂ --PO₃ H, x represents an integer selected from 1 to 6, andpreferably is 2, and y represents an integer selected from 0, 1, 2 or 3.Within this general formula especially preferred stabilisers includeethylenediamine tetra acetic acid (EDTA), ethylenediamine tetrakis(methylenephosphonic acid) (EDTMP), and diethylenetriamine pentakis(methylenephosphonic acid) (DTPMP). A further and particularly effectivestabiliser comprises cyclohexane-1,2-diamine tetrakis(methylenephosphonic acid), CDTMP. The amount of stabiliser is often upto 5% of the composition and in many instances is selected in the rangeof from 0.05 to 1%.

If present at all, a surfactant is present in bleaching compositionsonly in a small amount, such as up to about 5% and in many instancesfrom 0.1 to 2% of the composition. It can be selected from thesurfactants described subsequently herein for washing compositions.

The invention bleaching compositions will often comprise particulatemixtures, which can be stored loosely in conventional waxed boxes, oralternatively be enclosed in rupturable pouches or in porous orperforated bags or sacs through which bleaching solution can penetrate.Such mixtures can be obtained by dry blending the particulatecomponents, or they can be aggregated using conventional agglomerationor granulation techniques, using water or a removable solvent andoptionally a granulating aid hitherto described for use with an organicperoxyacid. Alternatively, by virtue of their demonstrated ability towithstand pressure, all but the least resistant invention peroxyacidscan be compressed in tablets and like bodies. Accordingly, it ispossible to provide peroxyacids in easy to use predetermined dosagelevels for the end user.

The bleaching compositions can be used by themselves, such as in apre-wash bleach or a post-wash rinsing stage of a multistage laundryprocess or in cleansing both absorbent or non-absorbent (sometimescalled "hard") surfaces. They are more usually employed in conjunctionwith a washing composition based upon surfactants. Naturally,surfactants and optional ingredients of washing compositions can bepremixed with the instant bleaching compositions to formbleach-containing washing compositions.

Washing compositions according to this further aspect of the presentinvention contain from 0.5 to 50% of the invention imido peroxyacids,from 1 to 90% surfactant, from 0 to 90% detergent builder, from 0 to 90%diluent and from 0 to 20% minor components. It will be recognised thatthe composition of the invention washing compositions range within verybroad limits. Choice of the peroxyacid in acid form can be beneficialherein, in order to minimise or avoid spotting problems that can occurif excessive local concentrations of active bleach should be allowed toremain in contact with a dyed fabric for too long.

In many preferred compositions according to the present invention, oneor more of the composition components are selected within the followingnarrower bands:

    ______________________________________                                        imido peroxyacid                                                                              1 to 25%, particularly 2 to 10%                               surfactant      2 to 40%, particularly 5 to 25%                               builder         1 to 60%, particularly 5 to 40%                               diluent         1 to 70%, particularly 5 to 50%                               minor components                                                                              1 to 10% in total.                                            ______________________________________                                    

The surfactants for incorporation in solid compositions of the presentinvention can be selected from particulate or flaky anionic, cationic,non-ionic, zwitterionic, amphoteric and ampholytic surfactants and canbe either natural soaps or synthetic. A number of suitable surfactantsare described in chapter 2 of Synthetic Detergents by A Davidsohn and B.M. Milwidsky (6th edition) published in 1978 by George Godwin Ltd andJohn Wiley & Sons, incorporated herein by reference. Without limiting tothese surfactants, representaitive sub-classes of anionic surfactantsare carboxylic acid soaps, alkyl aryl sulphonates, olefin sulphonates,linear alkane sulphonates, hydroxy-alkane sulphonates, long chain andOXO alcohol sulphates, sulphated glycerides, sulphated ethers,sulpho-succinates, alkane sulphonates, phosphate esters, sucrose estersand anionic fluorosurfactants; representative classes of cationicsurfactants include quaternary ammonium or quaternary pyridinium saltscontaining at least one hydrophobic alkyl or aralkyl group,representative classes of nonionic surfactants include condensates of along chain alkanol or an alkyl phenol with polyethylene oxides, orcondensates of long chain carboxylic acids or amines or amides withpolyethylene oxide, and related compounds in which the long chain moietyis condensed with an aliphatic polyol such as sorbitol or condensationproducts of ethylene and propylene oxides or fatty acid alkanolamidesand fatty acid amine oxides; representative classes ofamphoteric/zwitterionic surfactants include sulphonium and phosphoniumsurfactants, optionally substituted by an anionic solubilising group.The proportion of surfactant, expressed as a fraction of all thesurfactant present is often from 2/10 to 8/10ths anionic, from 0 to6/10ths nonionic, and from 0 to 3/10ths for the other surfactants.

It will be recognised by the knowledgable reader that many of theclasses of diluent described herein above for use in bleachingcompositions are also called detergent builders. These includespecifically alkali metal phosphates, particularly tripolyphosphate butalso tetrapyrophosphate and hexametaphosphate, especially the sodiumsalt of each, alkali metal, preferably, sodium carbonate, alkali metal,preferably, sodium borates, and the zeolites A, X and Y and clays likebentonite. Amongst organic compounds, the chelating compounds which weredescribed herein as peroxygen stabilisers can also function as detergentbuilders. Particularly preferred chelating builders includenitrilotrisodium trisacetate (NTA), EDTA, EDTMP and DTPMP. Suchchelating builders can be employed in a relatively small amount as anaugmenting builder and peroxygen stabiliser, such as of 1 to 10% , or incooperative partnership of equals in conjunction with a phosphatic orzeolitic or clay builder, the weight ratio of chelating to inorganicbuilders often being from 4:1 to 1:4, or alternatively they can beemployed as the principal builder in amounts of up to 40% such as in therange of 5 to 30% of the washing composition.

The other types of compounds that have been indicated to be suitable foruse as diluents in a bleaching composition, can also be employed for thesame primary purpose and secondary purpose, if any, in washingcompositions, although it will be recognised that the presence of aneffervescent system in washing compositions is comparatively rare. Forthe avoidance of doubt, persalts can be incorporated in the instantwashing compositions, preferably in an amount of up to 30%, such as 1 to20%, and sometimes in a weight ratio to the invention imido peroxyacidsof from 5:1 to 1:5. A diluent commonly present in these washingcompositions is sodium sulphate, often from 5 to 50%, because it alsofunctions as a processing aid. The previously mentioned salts thatenable a halogen to be generated in situ can likewise be present in thewashing compositions, which can then enjoy the alternative name ofsanitising compositions.

The washing compositions can contain a number of optional components,sometimes alternatively called auxiliary agents. These agents which caneach individually be included include soil anti redeposition agents(SARDs), dye transfer inhibitors, optical brightening agents (OBAs),stabilisers, corrosion inhibitors, bactericides, dyes, perfumes, foamenhancers, foam inhibitors, pH regulators and absorbents. The amount foreach auxiliary agent is often selected in the range of 0.02 to 0.2% fordyes and perfumes and from 0.1 to 2% for each of the other auxiliaryagents. It is preferable to select auxiliary agents which are known notto interact with peroxygen compounds during storage or to coat the agentwith or incorporate the agent in a known fashion within a matrix of adispersible material such as a wax or the many other film-formingsubstances proposed in the literature for separating organic peroxygencompounds from co-components, e.g. in EP-B-00 27 693 to InteroxChemicals Limited. Such substances can also function as granulating aids(binders), if the invention compositions are granulated or agglomerated.Examples of suitable SARDs include carboxymethyl cellulose particularlythe sodium salt, polyvinylpyrrolidone and examples of OBAs includederivatives of diaminostilbene sulphonic acid and1,3-diaryl-2-pyrazolines and aminocoumarins.

The invention washing compositions can be dampened or dissolved in alittle water for cleaning and disinfecting non-adsorbent surfaces suchas walls, floors, work surfaces, vessels, baths, sinks and sanitarywareof metal, plastics, ceramics or glass, wood and rubber.

One of the main intended uses of the washing compositions is to cleanseand indeed also disinfect soiled adsorbent materials such as householdlaundry items or other articles made especially from cotton, rayon, flaxor wool or man-made fibres such as polyesters or polyamides. Thecleansing processes can be carried out at ambient temperature or atelevated temperature up to the boiling temperature of the washingsolution. The more preferred washing temperature for laundry is from 30°to 60° C. In laundering, it is desirable to introduce sufficient washingcomposition and/or bleach additive composition to provide at least 5 ppmavox from the imido peroxyacid, and often from 10 to 50 ppm avox, ppmindicating parts per million by weight and avox indicating availableoxygen. This can often be provided by the introduction of the inventionwashing composition selected in the range of 1 to 25 gpl, or bleachadditive composition selected in the range of from 0.5 to 10 gpl, theselection taking into account the concentration of imido peroxyacidtherein. The presence of persalts in the wash can supplement avoxlevels, for example by amounts of from 10 to 100 ppm avox. In use,depending upon whether and the extent to which alkaline materials,especially builders, are present in the composition itself or in anyaccompanying washing composition, the compositions generate upondissolution either a mildly acidic through to especially a mildlyalkaline pH. It is preferred to generate a pH of from 7.5 to 9.5 andespecially around pH of 8 to about 9.0 to optimise bleaching/washingperformance from the peroxyacid.

For use in disinfection, it is often preferable to employ an inventionperoxyacid concentration of up to 200 ppm avox and in many instancesfrom 25 to 100 ppm avox. It is also suitable to employ a solutionspanning neutrality, from mildly acidic, such as at least pH 4 up tomildly alkaline, such as pH 9. In order to attain a pH in such a range,the choice of builders/diluents is so made as to avoid highly alkalinematerials and instead select those that generate mild acidity oralkaninity such as sodium dihydrogen phosphate.

The washing processes for laundry can be carried out in currentlyavailable equipment. Washing times typically range from about 10 minutesto 30 minutes. Hand washing and extended steeping using solutions of theinvention compositions can alternatively or additionally be used.Specialist variations of the invention compositions, such as thoseintended for nappy sanitisation/cleansing or for denture cleansing arepreferably used in the accepted manner for prior art compositions, forexample steeping a soiled nappy in a warm peracid-containing solutionfor several hours before washing it using laundry techniques.

Having described the invention in general terms, specific embodimentswill now be described more fully by way of example only.

EXAMPLES 1 AND 2 Preparation of Imido Peroxyacids

In each Example and Comparison, the reaction equation for the acidcatalysed reaction was ##STR4##

The general preparative route adopted for the first preparation of eachperoxyacid was as follows:

N-alkyl imido trimellitic acid starting materials were prepared bycondensing trimellitic anhydride with the appropriate n-alkylamine. Thesubsequent peroxidation is exemplified for n-butylamine-substitutedtrimellitimide. The results from IR and NMR analyses confirmed thepresence of a condensed aromatic imide and carboxylic acid moieties, andacid titration confirmed that there was only one acid group permolecule.

A weighed amount of butylimidotrimellitic acid (BITA) (10 g) wasintroduced into stirred methanesulphonic acid (70 mls) in a beaker,forming a solution at room temperature, approximately 22°/23° C. in thesafety cabinet. Hydrogen peroxide assaying 85% w/w approx. aqueoussolution, was pumped via a peristaltic pump with continued stirring intothe reaction mixture progressively during a period of about 5 to 10minutes at a rate controlled so that the mixture's temperature did notrise above 25° C., until a total amount of 4.5 moles per mole ofcarboxylic acid had been introduced, i.e. a 3.5 molar excess comparedwith the stoichiometric amount. The reaction mixture was then kept atroom temperature for a further 3 hours. At the end of the reaction asubstantial fraction of the carboxylic acid had been oxidised to thecorresponding peroxycarboxylic acid, which precipitated out of solutionand the mixture cooled to below about 5° C. in an ice bath.

The reaction mixture was poured into about 3 times as much iced waterper volume of reaction mixture, filtered and the filter cake washed asubstantial volume of ice cold water, until the wash water was abovepH3, and below pH5 and the filter cake was then air-dried.

The yield of solid was 9.5g having an avox content of 5.64 whichindicates a purity of 93% (theoretical avox 6.06%) and a "melting pointof 64°-65° C. The peroxyacid product was butyl imido peroxytrimelliticacid, BIPTA.

The avox was measured by a standard technique in which a measured weightof sample was dissolved in acetic acid, if necessary augmented withdichloromethane to ensure that the sample is completely dissolved. Thesample is then contacted with a measured amount of sodium carbonatestabilised sodium iodide, in the presence of ferric chloride, allowed toreact for 10 minutes in the dark, and the resultant solution is titratedagainst standardised sodium thiosulphate solution until the pale yellowcoloured solution becomes colourless. The result is compared with acorresponding titration against a blank solution, and from thedifference the avox is calculated.

All the isolated peroxyacid products were analysed by conventional IRand BIPTA also by NMR techniques to confirm the presence of imido andpercarboxylic acid groups in the product molecule.

For the products produced by the route of of Ex 1, e.g. BIPTA, HIPTA etcin the infra-red trace, a shoulder/peak was observed with its centre at1770 cm⁻¹, and a sharp peak at 1705 cm⁻¹, which corresponds to a fivemembered imide ring. A further peak was observed with a centre at about1720 cm⁻¹, indicative of carbonyl stretching in a peroxycarboxylic acidwhich is a substituent of an aromatic nucleus. There was some tendencyfor the two latter peaks to merge. It was also observed for bothproducts that there was a substantial absence of peaks at about 3360cm⁻¹, or in the regions of indicated the presence of an amide groupobtained by opening of the imide ring during the peroxidation reaction.The spectra for the corresponding imidocarboxylic acid startingmaterials contained two significant peaks, a peak or shoulder at 1770cm⁻¹ and a broad peak at about 1705 cm⁻¹, which correspond to the twopeaks for the imide structure, but the second one tending to merge witha similarly located carboxylic acid peak. Thus, from the IR data, it canbe deduced that the product retained its alkyltrimellitimido structureand gained a percarboxylic acid group.

    ______________________________________                                        NMR analysis                                                                  BIPTA was analysed by proton NMR. The chemical                                shifts and the attributions are given below                                   Chemical Shift                                                                              Integration  Attribution                                        ______________________________________                                        0.95         triplet  3          CH.sub.3                                     1.4          sextuplet                                                                              2          CH.sub.2                                     1.7          pentuplet                                                                              2          CH.sub.2                                     3.7          triplet  2          CH.sub.2                                     7.95                                                                                       multiplet                                                                              3          Aromatic H (× 3)                       8.4                                                                           ______________________________________                                    

It will be seen that the NMR confirms the presence of a N-butyl groupand 3 aromatic C-H groups.

EXAMPLES 2a-i

In these Examples, the route of Example 1 was followed, employing theappropriate other N-alkyl trimellitic acid as starting material. Thedescription of R, the % purity (ratio of measured to theoretical avox),% yield (based on carboxylic acid), and melting point of the productperoxyacid are summarised in Table 1 below.

                  TABLE 1                                                         ______________________________________                                        Ex No Name      R =      % purity                                                                             % yield MP °C.                         ______________________________________                                        2a    HIPTA     n-heptyl 96     88       80                                   2b    PrIPTA    n-propyl 96     90       97                                   2c    PIPTA     n-pentyl 95     94       73                                   2d    SIPTA     n-hexyl  92     91       64                                   2e    IPTA      H        99     42      175                                   2f    MIPTA     methyl   92     69      128                                   2g    EIPTA     ethyl    98     62      120                                   2h    iPrIPTA   isopropyl                                                                              90     86      132-134                               2i    sBIPTA    sec-butyl                                                                              96     91       91                                   ______________________________________                                    

EXAMPLE 3 Alternative Preparation of BIPTA

In this Example, a solution of Caro's acid was prepared by mixingsulphuric acid (98% w/w, 18.2 g) and hydrogen peroxide solution (85%w/w, 2.83 g) and demineralised water (2.36 g) with cooling to 12° C. Asolution of BITA (5 g) in sulphuric acid (98% w/w,15 g) was addeddropwise in the Caro's acid solution at a reaction temperaturemaintained at about 35° C., over about 5 minutes with stirring and thereaction continued for a further 75 minutes. The reaction mixture wasthen quenched by slow addition of ice/water (100 g), filtered and washedas in Example 1. The yield of product was 4.3 g having an avox of 4.56%avox and a purity of about 75%.

EXAMPLES 3a TO 3d

Example 3 was repeated in a modified form, employing the carboxylicacids ITA, PrITA, sBITA and PITA (5 g) as a particulate feed instead ofthe sulphuric acid solution of BITA. A Caro's acid solution was madefrom sulphuric acid (98% w/w, 23.1 g), hydrogen peroxide solution (85%w/w, 5.7 g) and demineralised water (1.2 g) at a temperature below 15°C. The carboxylic acids were introduced gradually with stirring into theCaro's acid solution maintained at about 40° C. and the reactioncontinued for 40 minutes. The mixture was cooled in an ice-bath to about10° C. and quenched by slow addition of ice/water, filtered and washedto pH3. The purity of the products isolated were respectively 95.5%,90%, 91.6% and 84.4%.

Comparison Aromatic Imido Peroxyacid

Phthalimido-2-peroxyacetic acid (TIP2), a compound according to Example1 of EP-A-0 325 289, was made in a similar process to that employed forExample 1 herein from commercially available phthalimido-2-acetic acid.

Peroxyacid Performance

The peroxyacids were subjected to a number of tests to determine theireffectiveness as a bleach, their hazard rating and their storagestability. The compound were also compared in these tests with areference peroxyacid, diperoxydodecanedioc acid, DPDDA, a peroxyacidthat has emerged during the last eight years as a favourite organicperoxide amongst washing composition manufacturers like Procter &Gamble.

The tests were carried out as follows:

Storage stability

In this test, weighed samples of the peroxyacid are individually sealedin glass phials with a bubbler cap that permits excess internal pressureto vent to atmosphere, and stored in a dark chamber that isthermostatically controlled to 32° C. The avox of the peroxyacid ismeasured shortly after its preparation i.e. A₀ and after predeterminedstorage intervals, A_(s), the measurement being made on entireindividual samples. The stability results of stored samples are A_(s)/A₀, quoted as a percentage, the higher the better.

Avox is measured using the same method as described hereinabove.

It will be recognized that the storage stability of the peroxyacid byitself is an extremely important characteristic of a peroxyacid, notonly because the compound is likely to be stored in that way before itis encorporated in specific compositions, but also because it representsthe intrinsic stability of the compound, the maximum attainable even ifthe remaining components of compositions containing it are benign.

A + indicates that the compound is according to the invention whereasa - indicates that it is present by way of comparison.

                  TABLE 2                                                         ______________________________________                                                Proportion of avox remaining after                                    Compound  1 week     4 weeks  longest/n weeks                                 ______________________________________                                        +IPTA     100        95       97/8 w                                          +MIPTA    97         98       98/8 w                                          +EIPTA    99         97       97/8 w                                          +PrIPTA   100        99       99/8 w                                          +BIPTA    97         81                                                       +sBIPTA   94         96       95/8 w                                          +PIPTA    99         100       98/12 w                                        +SIPTA    100        94        90/12 w                                        +HIPTA    100        95        95/12 w                                        -TIP2     100        87        13/16 w                                        -DPDDA    97         85                                                       ______________________________________                                    

This Table demonstrates that the storage stability of imidoaromaticperoxyacids depends very greatly upon the nature and disposition of thesubstituents, and that the comparison peroxyacid, TIP2, is markedlyinferior. The invention peroxyacid containing the sec-butyl, pentyl orheptyl substituent showed truly outstanding stabilisation.

Hazard Rating

Two tests are described below to demonstrate the hazard rating of theperoxyacid. They are respectively an impact sensitivity test and apressure-time test.

In the impact sensitivity test, a weight (in kg) is dropped once from ameasured height (in cm) onto a fresh sample of the peroxyacid held inthe anvil. The sample is thus subjected to an impact, normally expressedas kg-cm (1 kg-cm=9.8×10⁻² J) that is proportionate to the height andweight. The test is carried out many times at each impact strength, andis observed to see whether the sample responds, by charring, emittingsmoke or at worst undergoing a minor explosion. The tests start at a lowimpact strength and are continued at increasing strengths until thelimiting result is obtained, being the earlier of either 50% of thetests at that impact strength give positive results or a figure of 500kg-cm is reached, which past experience indicates to represent anon-impact-sensitive product. The limiting result in kg-cm is shown inTables summarising the results, the higher the better.

In the pressure-time test, 2 g samples of the test material is placedinside an 18 ml steel bomb, and its decomposition initiated. Theconsequential rise in pressure is monitored and plotted or displayedagainst elapsed time, expressed in milliseconds. In Table 3, the time isgiven for the pressure in the bomb generated by the sample to increasefrom 100 to 300 psi, i.e. from 6.895×10⁵ Pa to 2.068×10⁶ Pa, the longerthe better. The symbol oo indicates that a pressure of 300 psi was notreached, i.e. a period of infinite duration. By way of interpretation, atime of less than 30 milliseconds indicates that the material ispotentially explosive, a time of 30 to 60 milliseconds indicates that itis marginally explosive, and to allow a safety margin, it is preferredto be around 100 milliseconds or longer.

                  TABLE 3                                                         ______________________________________                                                     Hazards rating results                                           Compound       Impact kg-cm                                                                             p-t msec                                            ______________________________________                                        +BIPTA         >500       ∞                                             +HIPTA         >500       ∞                                             -TIP2            75       30                                                  -DPDDA         >500       30                                                  ______________________________________                                    

Trials on IPTA, MIPTA, EIPTA, PrIPTA, sBIPTA, PIPTA, and SIPTA gave thesame result as for BIPTA, except that a sample of IPTA (made in Example3a) gave a p-t of 120 msec.

From Table 3, it can be seen that the invention imidoperoxyacids wereall much safer, as demonstrated by the impact test than the comparisonimido peroxyacid TIP2, and in the pressure-time test, were significantlysafer than the reference compound DPDDA as well as TIP2. These testsshow that the selection of suitable substituents in aromatic imidoperoxyacid compounds is of crucial significance in order to obtain aproduct that is inherently safe to handle.

Bleach/washing evaluation

The effectiveness of the invention and comparison peroxyacids was testedby washing swatches of cotton cloth that had been preimpregnated in astandard manner with one of four representative stains, tea, red wine,grass and blue polish. The evaluations were carried out in a laboratoryscale washing machine, a "Tergotometer" (Trade Mark) available from theUS Testing Corporation, under identical standardised conditions. Thewashing solution comprised local Cheshire tap water, hardness of about160 to 180 ppm hardness as calcium carbonate, in which was dissolved aperoxyacid-free washing composition at 6.5 g/l. Composition NSPA used inall trials had the approximate analysis:

    ______________________________________                                        Composition       NSPA                                                        Component         % w/w                                                       ______________________________________                                        Anionic surfactant                                                                              9                                                           Nonionic surfactant                                                                             8                                                           Other organics    1                                                           Sodium carbonate  3                                                           Sodium sulphate   19                                                          Sodium phosphate  36                                                          Sodium silicate   10                                                          Sodium Borate     4                                                           Water             balance                                                     ______________________________________                                    

A weighed amount of peroxyacid was introduced into the washing solutionto provide a peracid avox of 25 ppm therein, assuming total dissolution.This corresponds to a molar concentration of 1.56×10⁻³ M monoperoxyacid.The washing solution was kept at pH9 and at 40° C. during the washingperiod of 20 minutes. The swatches were then rinsed and dried and theextent of stain removal was determined by comparing the reflectance ofthe washed cloth, R_(w), with that of the pre-washed, stained cloth,R_(s), and that of the unstained cloth, R_(u). The measurements wereobtained using an Instrumental Colour System "Micromatch" (Trade Mark)reflectance spectrophotomer equipped with a Xenon lamp filtered througha D65 conversion filter to approximate to CIE artificial daylight StainRemoval, expressed a s percentage, was calculated using the formula:

    %SR=100×[R.sub.w -R.sub.s ]/[R.sub.u -R.sub.s ]

It will be recognised that by demonstrating the washing capability ofthe peroxyacids in this way, the tests using the invention peroxyacidsare in themselves Examples of washing processes according to otheraspects of the present invention. Similarly, since the swatches had notbeen stored in sterile conditions before being washed, the washingprocedure will act simultaneously to disinfect them.

The results quoted below are the mean of two evaluations. Comparativeresults on the same stained cloths using the washing composition byitself, i.e. without any added peracid, are designated "base".

                  TABLE 4                                                         ______________________________________                                                   % Stain Removal                                                    Ex/Comp Peracid  Red                Blue  Average                             No      employed Wine   Grass Tea   Polish                                                                              Removal                             ______________________________________                                        C4      base     78     78    46    58    65                                  5       BIPTA    95     97    77    74    86                                  6       HIPTA    90     89    59    72    80                                  C6      DPDDA    91     94    74    61    80                                  ______________________________________                                    

From Table 4, it can be seen that the invention peracid are veryeffective bleaching agent at hand-hot washing temperatures, not only bycomparison with a peracid-free base composition, but showing verysimilar or superior effectiveness overall compared with DPDDA, althoughwith a distinct bias towards the more hydrophobic stains. The trialsdemonstrate in particular that the shorter alkyl substituted imidocompound, BIPTA has especially attractive washing performance and thatthe invention compounds as a class perform particularly well againsthydrophobic stains.

A repeat set of washing trials were also carried under the same washingconditions, employing the same base washing composition at the sameconcentration, and further samples of the four stains, to compare theeffectiveness of the N-n propyl- compound (PrIPTA), with DPDDA (eachproviding 25 ppm avox) and base composition alone. The average stainremoval was 64% for the base alone, 80% for DPDDA and over 81% forPrIPTA. This confirms that PrIPTA is a particularly effective bleachingagent over a range of domestic stains.

Further repeat sets of washing trials were conducted using the sameconditions as respectively comparisons C4 and C6 and Example 5, usingthe peroxyacids specified in Table 4A below.

                  TABLE 4A                                                        ______________________________________                                                   % Stain Removal                                                    Ex/Comp Peracid  Red                Blue  Average                             No      employed Wine   Grass Tea   Polish                                                                              Removal                             ______________________________________                                        C4A     base     73     78    59    49    65                                  E4i     IPTA     94     87    81    57    80                                  C4B     base     74     76    54    53    64                                  C4C     DPDDA    91     90    79    66    82                                  E4ii    MIPTA    90     87    83    51    78                                  E4iii   EIPTA    95     93    79    58    81                                  E4iv    PrIPTA   93     94    82    64    83                                  E4v     PIPTA    94     97    79    74    86                                  E4vi    SIPTA    93     98    79    80    88                                  C4D     base     78     78    46    58    65                                  C4E     DPDDA    91     94    74    61    80                                  E4vii   iPrIPTA  96     93    80    73    86                                  E4viii  sBIPTA   95     96    80    67    88                                  ______________________________________                                    

From Table 4A, it can be seen that the invention peroxyacids tested inExamples E4i through to E4viii performed substantially better than thebase washing composition alone, and that a number of the peroxyacids,including specifically PrIPTA, PIPTA, SIPTA, iPrIPTA and sBIPTA are seento be especially effective washing/bleaching compounds by virtue of thefact that they out-perform DPDDA.

Formulations

Representative formulations are made by dry mixing particulate inventionperoxyacid with a premixture of the remaining components of compositionsintended for particular uses which are specified in the respectivefollowing Tables. In the formulations, iPrIPTA (tq) contains 90% w/wactive peroxyacid and has a measured avox of 5.7% w/w; sBIPTA (tq)contains 96% w/w active peroxyacid and has a measured avox of 5.7% w/w;PIPTA (tq) contains 94% w/w active peroxyacid and has a measured avox of5.4% w/w; SIPTA (tq) contains 92% w/w active peroxyacid and has ameasured avox of 5.0% w/w; BIPTA (tq1) contains 73% w/w activeperoxyacid and has a measured avox of 4.4% w/w; BIPTA (tq2) contains 96%w/w active peroxyacid and has a measured avox of 5.8% w/w; HIPTA (tq)contains 86% w/w active peroxyacid and has a measured avox of 4.5% w/w.LAS represents a linear alkyl benzene sulphonate, sodium salt, averagealkyl length of C11.5, and OBA represents an optical brightening agent.Similar formulations, i.e. capable of delivering the same number ofmoles of peroxyacid as the representative formulations are obtained bysubstituting the calculated proportion of the replacement peroxyacid forthat shown, using the ratio of the known avox contents of the twoperoxyacids, and correspondingly adjusting the content of the filler orbulking agent that is normally employed in the formulations, such assodium sulphate or sodium chloride.

EXAMPLES 7 TO 9A

Bleach Additive Formulations are obtained by dry blending theparticulate components specified in Table 5.

                  TABLE 5                                                         ______________________________________                                        Example No  7      7A      8    8A    9    9A                                             %      %       %    %     %    %                                  Components  w/w    w/w     w/w  w/w   w/w  w/w                                ______________________________________                                        BIPTA (tq1) 9.2                                                               BIPTA (tq2)                27.6                                               sBIPTA (tq)        7.0                                                        PIPTA (tq)                      29.7                                          SIPTA (tq)                                 63.8                               HIPTA (tq)                            71.1                                    LAS         3      3       4    4     5    5                                  OBA + chelate                                                                             0.2    0.2     0.2  0.2   0.2  0.2                                Sodium sulphate                                                                           87.6   89.8    68.2 66.1  23.7 31.0                               ______________________________________                                    

Dosing of formulations at 1.25 gpl provides respectively approximateavox concentrations in solution of 5 ppm for 7 and 7A, 20 ppm for 8 and8A, and 40 ppm for 9 and 9A. Solid bleach additive compositionscontaining a pH buffer to lower the solution pH closer to about pH 8.5,and hence improve stain removal are made by replacing about 10% w/w ofthe sodium sulphate by boric acid.

EXAMPLES 10 TO 15

Representative washing compositions according to the present inventionare made by dry mixing the particulate invention peroxyacid with a blendof the other components shown in Table 6. The abbreviations STPP andPBS1 represent respectively sodium tripolyphosphate and sodium perboratemonohydrate. The chelate is EDTMP, ethylene diamino (tetramethylenephosphonate), Na salt or CDTMP, cyclohexane diamino(tetramethylenephosphonic acid).

Use of Example formulations 10 to 15 at a concentration of 8 gpl in thewashing liquor, a typical level for front loading washing machines inEurope, results in peracid avox concentrations of approximately 10, 20,30, 15, 25, and 35 ppm respectively.

                  TABLE 6                                                         ______________________________________                                        Example No   10     11      12   13    14   15                                             %      %       %    %     %    %                                 Components   w/w    w/w     w/w  w/w   w/w  w/w                               ______________________________________                                        BIPTA (tql)  2.9                                                              HIPTA (tq)          5.6                                                       BIPTA (tq2)                 6.5                                               sBIPTA (tq)                      3.3                                          PIPTA (tq)                             5.8                                    SIPTA (tq)                                  8.8                               LAS          7.0    9.6     8.6  7.0   6.0  6.0                               Alcohol Ethoxylate                                                                         5.1    3.8     5.7  2.5   6.0  7.0                               STPP         34.0   26.1         40.0  30.0 30.0                              Zeolite A                   22.5                                              Carboxylate builder 2.0     15.0                                              Sodium sulphate                                                                            13.8   36.8    24.8 18.8  24.2 16.4                              Sodium silicate                                                                            14.0   6.7     7.6  6.5   5.0  5.0                               Soap         6.5                 3.0   3.0  2.0                               Buffer (boric acid)                                                                        10.0                10.0  10.0 10.0                              PBS1                                        9.0                               CMC          1.0    1.0     1.0  1.0   1.0  1.0                               Minors (Chelate +                                                                          0.4    0.4     0.4  0.6   0.3  0.5                               OBA + Perfume etc)                                                            Water        balance                                                          ______________________________________                                    

EXAMPLES 16 TO 18A

Representative Sanitizer Formulations are made by dry mixing thespecified invention peroxyacids with the other particulate componentsspecified in Table 7.

When these formulations are dosed into a nappy (or similar article)sanitising solution in an amount of 5 gpl, the invention peroxyacidsprovide an approximate avox of respectively 15 ppm for 16, 16A, 25 ppmfor 17, 17A and 35 ppm for 18, 18A.

                  TABLE 7                                                         ______________________________________                                                   Example No                                                         Components % w/w                                                                           16     16A     17   17A  18    18A                               ______________________________________                                        BIPTA (tql)  6.8                                                              HIPTA (tq)                  11.1                                              iPrITA (tq)         5.3                                                       sBIPTA (tq)                      8.8                                          PIPTA (tq)                            13.0                                    SIPTA (tq)                                  14.0                              LAS          9.0    9.0     7.0  7.0  5.0   5.0                               Sodium carbonate                                                                           20.0   20.0    23.0 23.0                                         STPP         10.0   10.0    10.0 10.0 10.0  10.0                              Sodium bicarbonate                    26.0  26.0                              Sodium chloride                                                                            45.7   47.2    47.2 49.5 45.2  44.2                              Borax        8.5    8.5                                                       Organic chelate             1.2  1.2  0.8   0.8                               ______________________________________                                    

EXAMPLES 19 TO 21A

Particulate dilute disinfectant compositions are made by dry mixing thecomponents specified in Table 8.

                  TABLE 8                                                         ______________________________________                                                   Example No                                                         Components % w/w                                                                           19     19A     20   20A  21    21A                               ______________________________________                                        BIPTA (tq1)  6.8                                                              HIPTA (tq)                  11.3                                              iPrITA (tq)         5.3                                                       BIPTA (tq2)                           12.1                                    PIPTA (tq)                       9.4                                          SIPTA (tq)                                  14.0                              Sodium dihydrogen                                                                          10.0   10.0    10.0 10.0 10.0  10.0                              phosphate                                                                     Boric acid   5.0    5.0     5.0  5.0  5.0   5.0                               Corrosion Inhibitor                                                                        1.0    1.0     1.0  1.0  1.0   1.0                               Perfume      0.5    0.5     0.5  0.5  0.5   0.5                               Sodium sulphate                                                                            76.7   78.2    72.2 74.1 71.4  69.5                              ______________________________________                                    

When these formulations are employed at a dose level of 1 glp in anaqueous medium requiring disinfection, the approximate concentration ofavox therein is respectively 3 ppm for 19, 19A, 5 ppm for 20, 20A and 7ppm for 21, 21A.

EXAMPLES 22 TO 24

Disintegrating Tablet compositions, suitable for dentures are made bydry mixing the components given in Table 9 below, and then subjectingthem to compression in the mould of a tabletting machine to make tabletweighing about 4 g. The polyethyleneglycol binder av mol weight 6000 isdesignated PEG 6000, the disintegrant was a cross linkedpolyvinylpyrrolidone available under the Trademark POLYPLASDONE XL andthe lubricant was sodium lauryl sulphate.

                  TABLE 9                                                         ______________________________________                                        Example No      22        23       24                                         Particulate Components                                                                        % w/w     % w/w    % w/w                                      ______________________________________                                        BIPTA (tq1)     9.7                                                           HIPTA (tq)                11.9                                                PIPTA (tq)                         11.6                                       Succinic acid   25.2      15.0     15.0                                       Sodium Bicarbonate        25.5     40.0                                       Sodium Carbonate                                                                              10.0                                                          PEG 6000 (binder)                                                                             6.0       6.0      6.0                                        PVP disintegrant                                                                              1.0       1.0      1.0                                        Lubricant       0.2       0.2      0.2                                        Sodium sulphate 47.9      40.4     26.0                                       ______________________________________                                    

When one tablet of composition 22, 23 or 24 is introduced into water itgenerates respectively 17, 21.5 or 25 mg avox.

We claim:
 1. An organic peroxyacid which satisfies formula (1): ##STR5##in which R represents hydrogen or a low molecular weight alkyl groupcontaining up to 8 linear carbon atoms.
 2. A peroxyacid according toclaim 1 in which R represents a linear n-alkyl or branched alkyl groupcontaining from 3 to 7 carbon atoms.
 3. A peroxyacid according to claim1 in which R represents hydrogen, propyl, iso-propyl, butyl, iso-butyl,sec-butyl, pentyl or hexyl.
 4. A bleach composition containing from 1 to80% w/w of an organic peroxyacid which satisfies the formula (1):##STR6## in which R represents hydrogen or a low molecular weight alkylgroup containing up to 8 linear carbon atoms and from 99 to 20% w/w of adiluent.
 5. A washing composition containing from 0.5 to 50% w/w of anorganic peroxyacid which satisfies the formula (1) ##STR7## in which Rrepresents hydrogen or a low molecular weight alkyl group containing upto 8 linear carbon atoms, from 1 to 90% surfactant, from 0 to 90%detergent builder, from 0 to 99% diluent and from 0 to 20% auxilliaryagents.
 6. In a method of bleaching in which an item to be bleached iscontacted with an effective amount of a bleaching agent, the improvementwherein the bleaching agent comprises a peroxyacid which satisfies theformula: ##STR8## in which R represents hydrogen or a low molecularweight alkyl group containing up to 8 linear carbon atoms.
 7. A methodaccording to claim 6 wherein R represents a linear n-alkyl or branchedalkyl group containing from 3 to 7 carbon atoms.
 8. A method accordingto claim 6 wherein R represents hydrogen, propyl, iso-propyl, butyl,iso-butyl, sec-butyl, pentyl or hexyl.
 9. A method according to claim 6wherein said bleaching agent is provided in a bleaching compositionwhich further comprises from 99 to 20% w/w of a diluent.
 10. In a methodof disinfecting in which an item to be disinfected is contacted with aneffective amount of a disinfecting agent, the improvement wherein thedisinfecting agent comprises a peroxyacid which satisfies the formula:##STR9## in which R represents hydrogen or a low molecular weight alkylgroup containing up to 8 linear carbon atoms.
 11. A method according toclaim 10 wherein R represents a linear n-alkyl or branched alkyl groupcontaining from 3 to 7 carbon atoms.
 12. A method according to claim 10wherein R represents hydrogen, propyl, iso-propyl, butyl, iso-butyl,sec-butyl, pentyl or hexyl.
 13. A method according to claim 6 whereinsaid disinfecting agent is provided in a disinfecting composition whichfurther comprises from 99 to 20% w/w of a diluent.
 14. A method ofwashing in which an item to be washed is contacted with an effectiveamount of a washing agent, the improvement wherein the washing agentcomprises a peroxyacid which satisfies the formula: ##STR10## in which Rrepresents hydrogen or a low molecular weight alkyl group containing upto 8 linear carbon atoms.
 15. A method according to claim 14 wherein Rrepresents a linear n-alkyl or branched alkyl group containing from 3 to7 carbon atoms.
 16. A method according to claim 14 wherein R representshydrogen, propyl, iso-propyl, butyl, iso-butyl, sec-butyl, pentyl orhexyl.
 17. A method according to claim 14 wherein said washing agent isprovided in a disinfecting composition which further comprises from 1 to90% surfactant, from 0 to 90% detergent builder, from 0 to 90% diluent,and from 0 to 20% auxilliary agents.